I think Sehwag has been fallible in the past, but recently he seems to be building up a head of steam, and scoring consistently against all types of bowling and attacks. I really rate him at the moment, and he has he chance if he scores consistently now, to be remembered as a great, and not merely as good.
He's similar to guy from he 60's Colin Milburn, who didn't believe in running, and smashed it everywhere as an opener - he was less consistant though.